[XeTeX] Σχετ: Re: Grey fonts with XeTeX

Zdenek Wagner zdenek.wagner at gmail.com
Tue Jun 28 10:15:47 CEST 2016

Hi all,

the idea of spot colours is qite simple. Imagine that you want to
print a monochrome document, but not black, let say red on white. The
red colour will have to be mixed from yellow and magenta possibly with
a small amount of black and/or cyan. In such a case you will have to
prepare four separations. The software does it easily but you will
have to pay them and pay all CMYK colours. If you use red as a spot
colour, you need just one separation and one colour. The document can
be printed as if it were black&white but they will use a red colour
instead of the black one. I do it quite often without using the
machinery of spot colours, I just instruct them to use the spot colour
and put the instruction to the crop marks. It is even possible to use
two spot colours because such offset printers exist that can print in
two colours. Thus I use black + red. My PDF is prepared to contain
only black and magenta separations (yellow and cyan are empty) and I
put an instraction that the magenta separation should be printed with
a specified red. I do not fully understand the machinery of spot
colours in PDF. I hope that it allows to see visually the right colour
on screen while providing the correct separations. Each Pantone colour
has its approximate CMYK values so you can have realistic preview. In
my simplistic method I see false colours.

Usage of spot colours has these advantages:

1. It is cheaper because less separations are needed (unless you have
too many spot colours)
2. You have the possibility to use more saturated colour than can be
created by CMYK (colours that are out of CMYK gamut)
3. You put less ink on the paper which is technologically better
(prevents distorsion of the paper during drying the inks, the drying
is faster)

Spot colours are allowed in PDF/X.

Zdeněk Wagner

2016-06-27 15:46 GMT+02:00 Philip Taylor <P.Taylor at rhul.ac.uk>:
> Thank you for the suggestion, Apostolos, but in fact I'm not trying to use
> colour (/qua/ colour) at all.  Rather, I am trying to ensure that all pages
> that do not /require/ colour use only "true" black, CMYK black or greyscale
> -- not RGB black, for example.
> ** Phil.
> --------
> Apostolos Syropoulos wrote:
> If you want to use spot colors, then you
> could try to use the xespoycolor
> package. I had no idea what spot colors
> are when a publisher asked me to
> use spot colors for colored frames.
> So I ported the spotcolor package
> to solve the problem of colored frames
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